3,4-Dihydro-2,2-dimethyl 2H-1-benzopyran-6-butyric acid (DBA) is a potent antisickling and desickling agent, which does not covalently bind to hemoglobin S chains, and its acute toxicity agiainst mice is low. The objective of the proposed research is to gain insight into its biochemical mode of action by studying its effect on (a) gelation of Hb S (b) the level of 2,3 DPG and P50 of sickle cells and sickle hemolysate (c) Ca ions accumulation in sickle cells (d) globin synthesis of sickle reticulocytes and the preferential binding of Beta s to stroma (e) cellular enzymes of the Emden Meyerhof pathway and the hexose monophosphate shunt (f) the mechanical instability of oxyhemoglobin S. These studies will also improve our understanding of the pathophysiology of sickling.